function sData = cargar_unicamente_directos(filename)
    tmp = som_read_data(filename);
    directos = tmp.data(1:2:length(tmp.data),:);
    labels = tmp.labels(1:2:length(tmp.labels),: );
    
    sData = tmp;
    sData.data = directos;
    sData.labels = labels;
end 
